CLASS C POWER AMPLIFIER

Class C Power Amplifier

A class C power amplifier is biased to operate for less than 180¤ of the input signal cycle.

The tuned circuit in the output, however will provide a full cycle of output signal for the fundamental or resonant Frequency of the tuned circuit. The use of such amplifier is therefore, limited for a fixed frequency, as occurs in communication circuits.

Operation of a class C circuit is not intended primarily for large signal or power amplifiers.

WORKING of Class C Power Amplifier

In class C operation, collector current flows for less than one half cycle of the input signal.

The class C operation is achieved by reverse biasing the emitter-base junction,
which sets the dc operating point below cutoff and allows only the portion of the input signal that
overcomes the reverse bias to cause collector current flow. if an input signal amplitude is increased to the point that the transistor goes into saturation and cutoff, it is then called an OVERDRIVEN amplifier.

Application Of Class C Power Amplifier

The class C operated amplifier is used as a radio-frequency amplifier in transmitters.